diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 28567d457613..29fcb0689a91 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -81,24 +81,44 @@ void pci_configure_aspm_l1ss(struct pci_dev *pdev) void pci_save_aspm_l1ss_state(struct pci_dev *pdev) { + struct pci_dev *parent = pdev->bus->self; struct pci_cap_saved_state *save_state; - u16 l1ss = pdev->l1ss; u32 *cap; /* + * If this is a Downstream Port, we never restore the L1SS state + * directly; we only restore it when we restore the state of the + * Upstream Port below it. + */ + if (pcie_downstream_port(pdev) || !parent) + return; + + if (!pdev->l1ss || !parent->l1ss) + return; + + /* * Save L1 substate configuration. The ASPM L0s/L1 configuration * in PCI_EXP_LNKCTL_ASPMC is saved by pci_save_pcie_state(). */ - if (!l1ss) + save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS); + if (!save_state) return; - save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS); + cap = &save_state->cap.data[0]; + pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cap++); + pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cap++); + + /* + * Save parent's L1 substate configuration so we have it for + * pci_restore_aspm_l1ss_state(pdev) to restore. + */ + save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS); if (!save_state) return; cap = &save_state->cap.data[0]; - pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL2, cap++); - pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL1, cap++); + pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, cap++); + pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, cap++); } void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) @@ -1250,16 +1270,16 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) parent_link = link->parent; /* - * link->downstream is a pointer to the pci_dev of function 0. If - * we remove that function, the pci_dev is about to be deallocated, - * so we can't use link->downstream again. Free the link state to - * avoid this. + * Free the parent link state, no later than function 0 (i.e. + * link->downstream) being removed. * - * If we're removing a non-0 function, it's possible we could - * retain the link state, but PCIe r6.0, sec 7.5.3.7, recommends - * programming the same ASPM Control value for all functions of - * multi-function devices, so disable ASPM for all of them. + * Do not free the link state any earlier. If function 0 is a + * switch upstream port, this link state is parent_link to all + * subordinate ones. */ + if (pdev != link->downstream) + goto out; + pcie_config_aspm_link(link, 0); list_del(&link->sibling); free_link_state(link); @@ -1270,6 +1290,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) pcie_config_aspm_path(parent_link); } + out: mutex_unlock(&aspm_lock); up_read(&pci_bus_sem); } |